/*
 * Copyright (c) 2020 MANAAI.
 *
 * This file is part of trt_onnx2
 * (see http://manaai.cn).
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

#pragma once

#include <cassert>
#include <ctime>
#include <iomanip>
#include <iostream>
#include <ostream>
#include <sstream>
#include <string>

#include "NvInferRuntimeCommon.h"

using Severity = nvinfer1::ILogger::Severity;

class LogStreamConsumerBuffer : public std::stringbuf {
 public:
  LogStreamConsumerBuffer(std::ostream& stream, const std::string& prefix,
                          bool shouldLog)
      : mOutput(stream), mPrefix(prefix), mShouldLog(shouldLog) {}

  LogStreamConsumerBuffer(LogStreamConsumerBuffer&& other)
      : mOutput(other.mOutput) {}

  ~LogStreamConsumerBuffer() {
    // std::streambuf::pbase() gives a pointer to the beginning of the buffered
    // part of the output sequence std::streambuf::pptr() gives a pointer to the
    // current position of the output sequence if the pointer to the beginning
    // is not equal to the pointer to the current position, call putOutput() to
    // log the output to the stream
    if (pbase() != pptr()) {
      putOutput();
    }
  }

  // synchronizes the stream buffer and returns 0 on success
  // synchronizing the stream buffer consists of inserting the buffer contents
  // into the stream, resetting the buffer and flushing the stream
  virtual int sync() {
    putOutput();
    return 0;
  }

  void putOutput() {
    if (mShouldLog) {
      // prepend timestamp
      std::time_t timestamp = std::time(nullptr);
      tm* tm_local = std::localtime(&timestamp);
      std::cout << "[";
      std::cout << std::setw(2) << std::setfill('0') << 1 + tm_local->tm_mon
                << "/";
      std::cout << std::setw(2) << std::setfill('0') << tm_local->tm_mday
                << "/";
      std::cout << std::setw(4) << std::setfill('0') << 1900 + tm_local->tm_year
                << "-";
      std::cout << std::setw(2) << std::setfill('0') << tm_local->tm_hour
                << ":";
      std::cout << std::setw(2) << std::setfill('0') << tm_local->tm_min << ":";
      std::cout << std::setw(2) << std::setfill('0') << tm_local->tm_sec
                << "] ";
      // std::stringbuf::str() gets the string contents of the buffer
      // insert the buffer contents pre-appended by the appropriate prefix into
      // the stream
      mOutput << mPrefix << str();
      // set the buffer to empty
      str("");
      // flush the stream
      mOutput.flush();
    }
  }

  void setShouldLog(bool shouldLog) { mShouldLog = shouldLog; }

 private:
  std::ostream& mOutput;
  std::string mPrefix;
  bool mShouldLog;
};

//!
//! \class LogStreamConsumerBase
//! \brief Convenience object used to initialize LogStreamConsumerBuffer before
//! std::ostream in LogStreamConsumer
//!
class LogStreamConsumerBase {
 public:
  LogStreamConsumerBase(std::ostream& stream, const std::string& prefix,
                        bool shouldLog)
      : mBuffer(stream, prefix, shouldLog) {}

 protected:
  LogStreamConsumerBuffer mBuffer;
};

//!
//! \class LogStreamConsumer
//! \brief Convenience object used to facilitate use of C++ stream syntax when
//! logging messages.
//!  Order of base classes is LogStreamConsumerBase and then std::ostream.
//!  This is because the LogStreamConsumerBase class is used to initialize the
//!  LogStreamConsumerBuffer member field in LogStreamConsumer and then the
//!  address of the buffer is passed to std::ostream. This is necessary to
//!  prevent the address of an uninitialized buffer from being passed to
//!  std::ostream. Please do not change the order of the parent classes.
//!
class LogStreamConsumer : protected LogStreamConsumerBase, public std::ostream {
 public:
  //! \brief Creates a LogStreamConsumer which logs messages with level
  //! severity.
  //!  Reportable severity determines if the messages are severe enough to be
  //!  logged.
  LogStreamConsumer(Severity reportableSeverity, Severity severity)
      : LogStreamConsumerBase(severityOstream(severity),
                              severityPrefix(severity),
                              severity <= reportableSeverity),
        std::ostream(&mBuffer)  // links the stream buffer with the stream
        ,
        mShouldLog(severity <= reportableSeverity),
        mSeverity(severity) {}

  LogStreamConsumer(LogStreamConsumer&& other)
      : LogStreamConsumerBase(severityOstream(other.mSeverity),
                              severityPrefix(other.mSeverity),
                              other.mShouldLog),
        std::ostream(&mBuffer)  // links the stream buffer with the stream
        ,
        mShouldLog(other.mShouldLog),
        mSeverity(other.mSeverity) {}

  void setReportableSeverity(Severity reportableSeverity) {
    mShouldLog = mSeverity <= reportableSeverity;
    mBuffer.setShouldLog(mShouldLog);
  }

 private:
  static std::ostream& severityOstream(Severity severity) {
    return severity >= Severity::kINFO ? std::cout : std::cerr;
  }

  static std::string severityPrefix(Severity severity) {
    switch (severity) {
      case Severity::kINTERNAL_ERROR:
        return "[F] ";
      case Severity::kERROR:
        return "[E] ";
      case Severity::kWARNING:
        return "[W] ";
      case Severity::kINFO:
        return "[I] ";
      case Severity::kVERBOSE:
        return "[V] ";
      default:
        assert(0);
        return "";
    }
  }

  bool mShouldLog;
  Severity mSeverity;
};

//! \class Logger
//!
//! \brief Class which manages logging of TensorRT tools and samples
//!
//! \details This class provides a common interface for TensorRT tools and
//! samples to log information to the console, and supports logging two types of
//! messages:
//!
//! - Debugging messages with an associated severity (info, warning, error, or
//! internal error/fatal)
//! - Test pass/fail messages
//!
//! The advantage of having all samples use this class for logging as opposed to
//! emitting directly to stdout/stderr is that the logic for controlling the
//! verbosity and formatting of sample output is centralized in one location.
//!
//! In the future, this class could be extended to support dumping test results
//! to a file in some standard format (for example, JUnit XML), and providing
//! additional metadata (e.g. timing the duration of a test run).
//!
//! TODO: For backwards compatibility with existing samples, this class inherits
//! directly from the nvinfer1::ILogger interface, which is problematic since
//! there isn't a clean separation between messages coming from the TensorRT
//! library and messages coming from the sample.
//!
//! In the future (once all samples are updated to use Logger::getTRTLogger() to
//! access the ILogger) we can refactor the class to eliminate the inheritance
//! and instead make the nvinfer1::ILogger implementation a member of the Logger
//! object.

class Logger : public nvinfer1::ILogger {
 public:
  Logger(Severity severity = Severity::kWARNING)
      : mReportableSeverity(severity) {}

  //!
  //! \enum TestResult
  //! \brief Represents the state of a given test
  //!
  enum class TestResult {
    kRUNNING,  //!< The test is running
    kPASSED,   //!< The test passed
    kFAILED,   //!< The test failed
    kWAIVED    //!< The test was waived
  };

  //!
  //! \brief Forward-compatible method for retrieving the nvinfer::ILogger
  //! associated with this Logger \return The nvinfer1::ILogger associated with
  //! this Logger
  //!
  //! TODO Once all samples are updated to use this method to register the
  //! logger with TensorRT, we can eliminate the inheritance of Logger from
  //! ILogger
  //!
  nvinfer1::ILogger& getTRTLogger() { return *this; }

  //!
  //! \brief Implementation of the nvinfer1::ILogger::log() virtual method
  //!
  //! Note samples should not be calling this function directly; it will
  //! eventually go away once we eliminate the inheritance from
  //! nvinfer1::ILogger
  //!
  void log(Severity severity, const char* msg) override {
    LogStreamConsumer(mReportableSeverity, severity)
        << "[TRT] " << std::string(msg) << std::endl;
  }

  //!
  //! \brief Method for controlling the verbosity of logging output
  //!
  //! \param severity The logger will only emit messages that have severity of
  //! this level or higher.
  //!
  void setReportableSeverity(Severity severity) {
    mReportableSeverity = severity;
  }

  //!
  //! \brief Opaque handle that holds logging information for a particular test
  //!
  //! This object is an opaque handle to information used by the Logger to print
  //! test results. The sample must call Logger::defineTest() in order to obtain
  //! a TestAtom that can be used with Logger::reportTest{Start,End}().
  //!
  class TestAtom {
   public:
    TestAtom(TestAtom&&) = default;

   private:
    friend class Logger;

    TestAtom(bool started, const std::string& name, const std::string& cmdline)
        : mStarted(started), mName(name), mCmdline(cmdline) {}

    bool mStarted;
    std::string mName;
    std::string mCmdline;
  };

  //!
  //! \brief Define a test for logging
  //!
  //! \param[in] name The name of the test.  This should be a string starting
  //! with
  //!                  "TensorRT" and containing dot-separated strings
  //!                  containing the characters [A-Za-z0-9_]. For example,
  //!                  "TensorRT.sample_googlenet"
  //! \param[in] cmdline The command line used to reproduce the test
  //
  //! \return a TestAtom that can be used in Logger::reportTest{Start,End}().
  //!
  static TestAtom defineTest(const std::string& name,
                             const std::string& cmdline) {
    return TestAtom(false, name, cmdline);
  }

  //!
  //! \brief A convenience overloaded version of defineTest() that accepts an
  //! array of command-line arguments
  //!        as input
  //!
  //! \param[in] name The name of the test
  //! \param[in] argc The number of command-line arguments
  //! \param[in] argv The array of command-line arguments (given as C strings)
  //!
  //! \return a TestAtom that can be used in Logger::reportTest{Start,End}().
  static TestAtom defineTest(const std::string& name, int argc,
                             char const* const* argv) {
    auto cmdline = genCmdlineString(argc, argv);
    return defineTest(name, cmdline);
  }

  //!
  //! \brief Report that a test has started.
  //!
  //! \pre reportTestStart() has not been called yet for the given testAtom
  //!
  //! \param[in] testAtom The handle to the test that has started
  //!
  static void reportTestStart(TestAtom& testAtom) {
    reportTestResult(testAtom, TestResult::kRUNNING);
    assert(!testAtom.mStarted);
    testAtom.mStarted = true;
  }

  //!
  //! \brief Report that a test has ended.
  //!
  //! \pre reportTestStart() has been called for the given testAtom
  //!
  //! \param[in] testAtom The handle to the test that has ended
  //! \param[in] result The result of the test. Should be one of
  //! TestResult::kPASSED,
  //!                   TestResult::kFAILED, TestResult::kWAIVED
  //!
  static void reportTestEnd(const TestAtom& testAtom, TestResult result) {
    assert(result != TestResult::kRUNNING);
    assert(testAtom.mStarted);
    reportTestResult(testAtom, result);
  }

  static int reportPass(const TestAtom& testAtom) {
    reportTestEnd(testAtom, TestResult::kPASSED);
    return EXIT_SUCCESS;
  }

  static int reportFail(const TestAtom& testAtom) {
    reportTestEnd(testAtom, TestResult::kFAILED);
    return EXIT_FAILURE;
  }

  static int reportWaive(const TestAtom& testAtom) {
    reportTestEnd(testAtom, TestResult::kWAIVED);
    return EXIT_SUCCESS;
  }

  static int reportTest(const TestAtom& testAtom, bool pass) {
    return pass ? reportPass(testAtom) : reportFail(testAtom);
  }

  Severity getReportableSeverity() const { return mReportableSeverity; }

 private:
  //!
  //! \brief returns an appropriate string for prefixing a log message with the
  //! given severity
  //!
  static const char* severityPrefix(Severity severity) {
    switch (severity) {
      case Severity::kINTERNAL_ERROR:
        return "[F] ";
      case Severity::kERROR:
        return "[E] ";
      case Severity::kWARNING:
        return "[W] ";
      case Severity::kINFO:
        return "[I] ";
      case Severity::kVERBOSE:
        return "[V] ";
      default:
        assert(0);
        return "";
    }
  }

  //!
  //! \brief returns an appropriate string for prefixing a test result message
  //! with the given result
  //!
  static const char* testResultString(TestResult result) {
    switch (result) {
      case TestResult::kRUNNING:
        return "RUNNING";
      case TestResult::kPASSED:
        return "PASSED";
      case TestResult::kFAILED:
        return "FAILED";
      case TestResult::kWAIVED:
        return "WAIVED";
      default:
        assert(0);
        return "";
    }
  }

  //!
  //! \brief returns an appropriate output stream (cout or cerr) to use with the
  //! given severity
  //!
  static std::ostream& severityOstream(Severity severity) {
    return severity >= Severity::kINFO ? std::cout : std::cerr;
  }

  //!
  //! \brief method that implements logging test results
  //!
  static void reportTestResult(const TestAtom& testAtom, TestResult result) {
    severityOstream(Severity::kINFO)
        << "&&&& " << testResultString(result) << " " << testAtom.mName << " # "
        << testAtom.mCmdline << std::endl;
  }

  //!
  //! \brief generate a command line string from the given (argc, argv) values
  //!
  static std::string genCmdlineString(int argc, char const* const* argv) {
    std::stringstream ss;
    for (int i = 0; i < argc; i++) {
      if (i > 0) ss << " ";
      ss << argv[i];
    }
    return ss.str();
  }

  Severity mReportableSeverity;
};

namespace {

//!
//! \brief produces a LogStreamConsumer object that can be used to log messages
//! of severity kVERBOSE
//!
//! Example usage:
//!
//!     LOG_VERBOSE(logger) << "hello world" << std::endl;
//!
inline LogStreamConsumer LOG_VERBOSE(const Logger& logger) {
  return LogStreamConsumer(logger.getReportableSeverity(), Severity::kVERBOSE);
}

//!
//! \brief produces a LogStreamConsumer object that can be used to log messages
//! of severity kINFO
//!
//! Example usage:
//!
//!     LOG_INFO(logger) << "hello world" << std::endl;
//!
inline LogStreamConsumer LOG_INFO(const Logger& logger) {
  return LogStreamConsumer(logger.getReportableSeverity(), Severity::kINFO);
}

//!
//! \brief produces a LogStreamConsumer object that can be used to log messages
//! of severity kWARNING
//!
//! Example usage:
//!
//!     LOG_WARN(logger) << "hello world" << std::endl;
//!
inline LogStreamConsumer LOG_WARN(const Logger& logger) {
  return LogStreamConsumer(logger.getReportableSeverity(), Severity::kWARNING);
}

//!
//! \brief produces a LogStreamConsumer object that can be used to log messages
//! of severity kERROR
//!
//! Example usage:
//!
//!     LOG_ERROR(logger) << "hello world" << std::endl;
//!
inline LogStreamConsumer LOG_ERROR(const Logger& logger) {
  return LogStreamConsumer(logger.getReportableSeverity(), Severity::kERROR);
}

//!
//! \brief produces a LogStreamConsumer object that can be used to log messages
//! of severity kINTERNAL_ERROR
//         ("fatal" severity)
//!
//! Example usage:
//!
//!     LOG_FATAL(logger) << "hello world" << std::endl;
//!
inline LogStreamConsumer LOG_FATAL(const Logger& logger) {
  return LogStreamConsumer(logger.getReportableSeverity(),
                           Severity::kINTERNAL_ERROR);
}

}  // anonymous namespace
